Commitments and Credit Risk - Lines of Credit (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Letters of Credit Outstanding, Amount	$ 13.4	$ 16.1
Commercial Lines of Credit
Letters of Credit Outstanding, Amount	1,300.0	1,000.0
Open-end Consumer Lines of Credit
Letters of Credit Outstanding, Amount	$ 175.7	$ 164.5